Spatially improved operators for excited hadrons on the lattice

TL;DR

This paper introduces a new method for constructing spatially optimized operators in lattice QCD to improve the spectroscopy of excited hadrons, enhancing the ability to study their properties.

Contribution

The paper develops a novel approach combining Jacobi smeared sources and the variational method to better isolate excited hadron states on the lattice.

Findings

Effective operators for excited states identified

Improved overlap with Roper and rho(1450) states demonstrated

Method shows promise for future lattice spectroscopy studies

Abstract

We present a new approach for determining spatially optimized operators that can be used for lattice spectroscopy of excited hadrons. Jacobi smeared quark sources with different widths are combined to construct hadron operators with different spatial wave functions. We use the variational method to determine those linear combinations of operators that have optimal overlap with ground and excited states. The details of the new approach are discussed and we demonstrate the power of the method using examples from quenched baryon and meson spectroscopy. In particular we study the Roper state and rho(1450) and discuss some physical implications of our tests.